Strip stock feed mechanism



April 7, 1942. c. FISCHER STRIP STOCK .FEED MECHANISM Filed April 26, 1941 3 Sheets-Sheet 1 ATTORNEY.

. Ap 7, 1942 c. FISCHER 2,278,921

STRIP STOCK FEED MECHANISM Filed April 26, 1941 3' Sheets-Sheet 2 INVENTOR.

A ril 7,.1942. c. FISCHER 2,278,921

STRIP STOCK FEED MECHANISM 7 Filed April 26, 1941 5 Sheets-Sheet s iii Ll i

IN VENTOR. fiarles 2505;

ATTORNEY.

Patented Apr. 7, 1942 OFFICE STRIP STOCK FEED MECHANISM Charles Fischer, Newark, N. J. Application April 26, 1941, Serial No. 390,525

Claims.

This invention relates to improvements in means for automatically feeding strip stock to power punch presses or other machines designed to shape or otherwise work upon such stock; and the invention has reference, more particularly, to improvements in reciprocable slide feed means \for automatically advancing strip stock to punch presses or other machines.

Automatic slide feed mechanisms for advancing strip stock, step by step, to punch presses or other machines are well known to the art, and usually comprise a reciprocable carriage provided with a pivotally mounted jaw plate means to grip and advance the stock on forward movement of the carriage, but adapted to release and ride freely over the stock during retractive carriage movement. In the use of such slide feed mechanism, when the same is automatically actuated in synchronism with the operations of a punch press or other stock working machine, especially, for example, when the latter is equipped with a plurality of successive die sets or other stock working elements adapted to perform successive shaping or working operations, difliculties are met with in initially starting in the leading end portion of the stock and shifting the same from one to another die set or working element to obtain an initial and properly coordinated sequence of the successive working operations. When the stock is started in by automatic operation of the slide feed mechanism, it frequently happens that the leading end thereof becomes distorted so as to be caught and obstructed from properly passing from one die set or working element to another, whereby jams occur which buckle and spoil the work. Such occurrences necessitate cutting away the ruined section of the stock and thereupon starting over again. This not only results in delay in performance of the required work, but also waste of stock, and, not infrequently, further. results in damage to expensive dies or other working elements.

Having the above difficulties in view, it is an object of this invention to provide, in combination with a reciprocable slide feed mechanism of the general character above mentioned, means to maintain the stock gripping jaw plate thereof in an inoperative or out of service position while nevertheless permitting reciprocable movements of the carriage, together with cooperative means manually controllable by the operator, to cause said stock gripping jaw plate to move to operative or service position during a retractive move:- ment of the carriage, and thereupon take up the work of automatically feeding the stock thereafter; whereby initial advancing of the leading end portion of the stock from one to another die set or other working element may be manually accomplished by the machine operator in such manner as to assure proper initial relation of the stock to each successive die set or working element, until a first complete succession of the series of operations required is attained, after which power operation may be initiated and automatic feeding ofthe stock may be begun by a properly timed shift of the stock gripping jaw to operative or service position in advance of a forward stroke or movement of the slide feed carriage, and without risk of disturbing or accidentally shifting the stock from its carefully adjusted relation to the die sets or other Iworking elements of the machine served by the eed.

Other objects of this invention, not at this time to that of Fig. 2, but showing the manner in which the jaw plate means of the carriage is thrown into operation during aretractive; movement of the carriage. I 7

Similar characters of. reference are employed in the above described views, to indicate corresponding parts.

An illustrative form of slide feed mechanism, having the novel features according to this invention, is shown in Fig. 1 of the drawings, attached to a power punch press P inposition to feed the strip stock S to the successive die sets a, b and c with which'the press is equipped.

The slide feed mechanism comprises a frame member ID suitably supported in connection with the bed block B of the press, whereby to mount the slide feed mechanism in position to feed the strip stock S across the die setsa, b and 0. Connected with said frame member ID are longitudinally spaced, upstanding transverse end members H. Afiixed to and between said end members II are laterally spaced guide rods l2.

Slidably mounted on said guide rods l2, by their slide portions l3, for reciprocation thereon, is a slide carriage having a bottom stock gripper plate l4 and transverse forward and rear walls l5 and I6 spaced above the latter to permit passage of the strip stock S over said gripper plate. Pivotally mounted on said slide carriage, by means of a transverse fulcrum pin ll, which is affixed to and between the slide portions |3 intermediate the forward and rear walls l5 and I6, is an oscillator block H which carries the stock gripping jaw plate l9. Said jaw plate I9 is slidably supported on said oscillator block I8 so as to be capable of vertical movements thereon toward and from the bottom stock gripper plate |4. Said oscillator block I8 is provided, at its upper end, with an offset head 20 which overhangs the upper end of said jaw plate l9. Threaded through said head 20 is a release bushing 2| disposed in align ment with said jaw plate, and extending axially through said bushing 2| is an adjusting screw 22 which bears on the upper end of the jaw plate IS. The jaw plate I9 is yieldably thrust into abutment with said adjusting screw by a lift spring 23 which is ailixed to said oscillator block I8 so that its free end portion operatively engages said jaw plate to exert upthrusting pressure thereon. By means of said adjusting screw 22, the jaw plate l9 may be vertically adjusted, when the bushing 2| is turned down to its normal lowered position in the oscillator block l8, toward and from said bottom stock gripper plate l4, so as to space the lower operative end of the jaw plate in proper relation to the latter for th gripping therebetween of strip stock of selected thickness. Aflixed to the upper end of said release bushing 2| is an actuating lever arm 24. Said lever arm 24, when -'wung in clockwise direction to an arrested position against a stop pin 25 on the top of the oscillator block |8, turns the threaded release bushing 2| so as to move the same downward, and thereby to thrust down the jaw plate I9, against the tension of the lift spring 23, to a position permitting the same to operatively grip the strip stock S. When, however, said lever arm 24 is swung in anti-clockwise direction to an arrested position against another stop pin 26 on the top of the oscillator block I8, the release bushing 2| is thereby turned to an upwardly shifted position to thereupon permit the lift spring 23 to -'raise the jaw plate I9 to 9. released position wherein it is prevented from operatively gripping the strip stock S. The lever arm 24 is yieldably held in either of the above mentioned arrested positions to which it may have been moved by a pull spring 27, one end of which is attached to a post 28 carried by the lever arm, and the other end of which is anchored to bracket 29 affixed to the oscillator block l8. Also affixed to the upper end portion of the release bushing 2| is a rocker cam 30 having, in its periphery a suitably located radial shoulder 3| for purposes to be hereinafter set forth.

Means are provided for automatically operating the slide carriage and oscillator block in synchronized relation to the operations of the power punch press P served by the slide feed mechanism. To this end, the frame member I0 is provided, on its opposite sides, with laterally opposed upstanding bearing brackets 32 to support a transverse fulcrum pin 33. Pivotally mounted on this fulcrum 33 is a bell-crank lever 34. Pivotally connected with the lower arm 35 of said bellcrank lever are the rearward ends of a pair of links 36, the forward ends of which straddle the upper end portion of the oscillator block IS, the latter being pivotally connected thereto by a wrist pin 31. Said bell-crank lever is actuated by a ball crank-pin 38 adjustably mounted on a crank member 39 affixed upon the power crank shaft 40 of the punch press. The crank-pin 38 is connected by a connecting rod 4|, through a universal joint 42, with the upper arm 43 of said bell-crank lever 34. By adjusting the throw of the crank-pin 38, a corresponding adjustment of the throw of said bell-crank lever 34 may be at- 36, the initial backward movement of said links first swings back the oscillator block I8 to its rearward limit of movement, as determined by an adjustable stop screw 44 carried by the rear wall l6 of the slide carriage. Such back swing of the oscillator block l8 swings up the operative end of the jaw plate Hi to strip stock releasing position. Thereafter, continued retractive movement of the links 36 is transmitted to the slide carriage, which is drawn back preparatory to an ensuing forward strip stock feeding stroke thereof. To prevent overthrow of the retractive movement of said slide carriage, a stop bridge 45 is affixed to and between the guide rods 2, the same having an adjustable stop 46 which is engaged by the rear abutment member 41 carried by the rear wall of the slide carriage. Any suitable means may be provided .to prevent displacement or accidental shift of the strip stock S during retractive movement of the carriage, such e. g. as a spring pressed drag or pressure plate 43.

As the motion of the bell-crank lever 34 reverses, thereby swinging forward its lower arm 35 and thrusting forward the links 36, the initial forward movement of said links first swings forward the oscillator block l8 to its forward limit of movement, as determined by an adjustable stop screw 43 carried by the forward wall |6 of the slide carriage. The forward swing of the oscillator block I8 swings down the operative end of the jaw plate I! to strip stock gripping position. Thereafter, continued forward thrust of the links 36 is transmitted to the slide carriage, which is advanced so as to feed forward the strip stock S for the desired distance ready for repetition of punch press operation thereupon. To prevent overthrow of the forward movement of said slide carriage, an adjustable stop 5|! is affixed to the forward end member II of frame member In which is engageable by the forward abutment member 5| carried by the forward wall |5 of the slide carriage.

Fixed on the forward end member H of the frame member ID is an upstanding post 52. Pivotally mounted on said post 52 is a trip lever 53. having a trip hook 54 at its free end. Said trip lever 53 is provided with an angularly extending handle lever 55, by means of which the same may be manipulated, when its use is required.

In operation of the above described improved slide feed mechanism, when starting into the press the leading end of strip stock desired to be eventually automatically fed to the press, the lever arm 24 is swung in anti-clockwise direction against the stop pin 28, in which position it is yieldably held by the pull spring 21. Such movement of the lever arm 24 turns the threaded bushing 2| so as to cause the same, and the adjusting screw 22 carried thereby, to rise in oscillator block head 20, whereby to back away the adjusting screw 22 from the upper end of the jaw plate I9 so that the tensional thrust of the lift spring 23 will raise the jaw plate t .,a position in which it cannot cooperate with the gripper plate 14 during reciprocation of the slide carriage, and consequently leaving the strip stock S free to be manipulated or moved forward by hand.

The strip stock 8 being thus freed so as to be uneifected by operation of the slide feed mechanism, as coupled to be driven by and in synchronism with th press, the operator may cause the press plunger to be raised by manually or otherwise turning the crank-shaft 40,'and held in raised position, while inserting the leading end of the strip stock S for engagement by the first die set a, whereupon the press plunger may be caused to descend and perform a first operation upon the stock, and then to be again raised and held in raised position. After performance of the first operation, and while the press plunger is raised, the operator may then shift the strip stock S by hand, so as to carry the part upon which the first operation has been performed into position for engagement by the second die set I). In so doing, the operator may carefully adjust the stock upon which the first stage of the work has been performed in proper fitted relation and alignment with the second die set, while at the same time straightening or smoothing out any distortion of the stock which may have accidentally occurred. This having been done, the press plunger is again caused to descend and perform a successive first operation while at the same time performing a second operation on the previously worked section of the stock, whereupon th press plunger is again raised and held, while the operator again shifts the strip stock by hand so as to carry the initial worked section into position for engagement by the third die set 0. In so doing, the operator again may carefully adjust the worked sections of the stock to the die sets b and c. This having been done, the press plunger is caused to descend and complete the die operations on the leading end of the strip stock, whereupon the mechanism may be thrown into normal automatic operation.

The novel means provided by this invention whereby, upon throwing the mechanism into nor- Fig. 4, th trip hook 54 of said trip lever will ride over said rocker cam 30, and move into engagement with the radial shoulder 3| of the latter, which is positioned to receive such engagement when the lever arm 24 is disposed to engage the stop pin 26. Said rocker cam being thus engaged by the trip lever, the ensuing retractlve movement of the slide carriage carries the rocker cam therewith, but since the shoulder of its retractive movement.

3| of said rocker cam 30 is engaged bythe trip hook 54, said rocker cam, as it is carried back is caused to rotate in clockwise direction, thus swinging the lever arm 24 in clockwise direction past dead center position of the pull spring 21, whereby the latter pulls the lever arm 24 into engagement with the stop pin 25 (see Fig. 5). Such movement of the lever arm 24 turns the threaded bushing 2| so as to cause the same, and th adjusting screw '22 carried thereby, to descend in the oscillator block head 20, thereby thrusting down the jaw plate I9 into cooperative relation to the gripper plate I4, all of which occurs before the slide carriage reaches the limit As a consequence of this the jaw plate I 9 'is ready to grip and advance the strip stock on the ensuing forward movement of th slide carriage, and thereafter to continue in automatic strip stock feeding operation until the machine is stopped.

Having now described my invention, I claim:

1. In a strip stock feeding mechanism having means to operate the same in synchronized relation to mechanism to which said stock is to be fed thereby, a reciprocating feed means having an oscillator block, a feeding jaw plate carried by said block, release means on said block for moving said jaw plate into and out of service position, means to actuate said release means, and manually controlled means operative to be engaged with said actuating means on an advance movement of said feed means whereby, upon an ensuing retractive movement of the latter, to automatically operate said release means to move said jaw plate from an out of service to an in service position.

2. In strip stock feeding mechanism having means to operate the same in synchronized relation to themechanism to which said stock is to be fed thereby, a reciprocating feed means having an oscillator block, a feeding jaw plate carried by said block, release means on said oscillator block for moving said jaw plate into and out of service position, a rocker cam on said release means, and a manipulatable trip lever movable to engage said rocker cam on an advance movement of said feed means whereby, upon an ensuing retractive movement of the latter, to automatically actuate said release means to move said jaw plate from an out of service to an in service position.

3. In strip stock feeding mechanism having I means to operate the same in synchronized relation to the mechanism to which said stock is to be fed thereby, a reciprocating feed means having an oscillator block, a feeding jaw plate carried by said block, release means on said oscillator block for moving said jaw plate into and out of service position, and means to yieldably retain said release means in position to dispose said jaw plate selectively in either out of service or in service position, a rocker cam on said release means, and a manipulatable trip lever movable to engage said rocker cam on an advance movement of said feed means whereby, upon an ensuing retractive movement of the latter, to automatically actuate said release means to move said jaw plat from an out of service to an in service position.

4. In strip stock feeding mechanism having means to actuate the same in synchronized relation to mechanism to which said stock is to be fed thereby, a guide frame, a reciprocating feed means slidable on said guide frame, an oscillator block carried by said feed means, a feeding jaw plate carried by said block, a turnable release means threaded into said oscillator block for vertical movement therein, means to yieldably thrust said jaw plate into operative engagement with said release means whereby to partake of vertical movements thereof for raising and lowering said jaw plate from and to service position, means to turn said release means optionally in directions to raise or lower the same and said jaw plate, and manually controlled means mounted on said guide frame operative to engage said turning means on an advance movement of the latter, to automatically turn said release means in direction to lower the same and thus move said law plate from out of service to an in service position.

5. In strip stock feeding mechanism having means to actuate the same in synchronized relation to mechanism to which said stock is to be fed thereby, a guide frame, a reciprocating feed means slidable on said guide frame, an oscillator block carried by said feed means, a feeding law plate carried by said block, a turnable release means threaded into said oscillator block for vertical movement therein, means to yieldably thrust said jaw plate into operative engagement with said release means whereby to partake of vertical movements thereof for raising and lowering said jaw plate from and to service position, a lever arm affixed to said release means, stop means engageable by said lever arm to respectively limit the raising and lowering turning movements of said release means, pull-spring means connected with said lever arm to yieldably retain said lever arm in either such stopped position, a rocker cam on said release means. and a manipulatable trip lever mounted on said guide frame, said trip lever being movable to engage said rocker cam on an advance movement of said feed means whereby, upon an ensuing retractive movement of the latter, to automatically turn said release means in direction to lower the same and thus move said jaw plate from out of service to an in service position.

CHARLES FISCHER. 

